American Farm Publications, Inc.
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DowAgriSciences offering tool in battle against fescue toxicity
By JANE W. GRAHAM
BLACKSBURG, Va. (Sept. 22, 2015) — Fescue head suppression is probably something most people do not know about or have an interest in but for livestock producers, it can help them combat fescue toxicosis.
Pat Burch, a field research biologist with DowAgriSciences, introduced the research that has been done on the subject to folks attending the New River Valley Agriculture Field Day last month at Virginia Tech’s Kentland Farm.
He was one of several scientists dealing with many different types of plants to showcase their research plots during the event organized by Virginia Cooperative Extension agents for residents of the counties surrounding Kentland.
Burch told the group of about 65 people fescue is an important grass for livestock producers, especially those who raise cattle.
He gave an overview of the problems and solutions that come with fescue at the field day and showed plots where the seed heads had been suppressed and where they had not.
Soon after the introduction of the popular Kentucky 31 tall fescue, Burch said cattle producers began seeing reduction of animal production and signs of heat stress. Through the years these symptoms have been labeled as “fescue toxicosis” and been found to be caused by a fungus living within the plants. The fungus produces a toxic group of compounds called ergot alkaloids.
According to Dow, annual losses to the nation’s livestock industry from the fungus is estimated to be $1 billion.
“Economic losses are largely associated with reductions in pregnancy rates and milk production, poor calf weaning weights and reduced average daily gains in stocker cattle,” Burch said.
Problems with cattle grazing fescue begin to occur in May and June when the seed heads are forming and grass is growing rapidly. The animals get a big dose of fescue just when the seed heads are forming on the plant’s reproductive stalks, he said. Fescue seed heads have between three and six times the alkaloids as the fescue leaf blades so keeping the grass from heading can improve performance, Burch said.
In an interview after the field day, he talked in more detail about how to grow healthy grass for healthy cattle. Burch cited work done by Ben Goff, a graduate student at the University of Kentucky and many others not associated with the company.
Burch focused on using broad-spectrum weed and brush control herbicide like Dow’s Chaparral to suppress the fescue seed heads. Burch recommended applications as early as three weeks before seed head emergence and as late as the fescue’s early boot stage.
Research leading to this new tool in the battle has been going on for more than eight years. Burch said Dow began looking at whether or not suppressing the seed head development would reduce toxicity. He indicated much of the research has been driven by the private sector and trials have been done on private farms.
Burch added a challenge has been finding the right time and amount for application to get consistent results. He said researchers have also found using this means more rigorous management of pastures. It has been found to work well in rotational grazing as it helps prevent overgrazing.
He said livestock grazing in the Valley of Virginia is especially vulnerable to the problems caused by grazing endophyte infected fescue. The area that basically cradles the Interstate 81 corridor is a major player in the state’s cattle industry.
“Tall fescue’s tolerance to extreme temperatures, drought, poor soil fertility, heavy grazing and pests have made it a reliable fore forage base for pastures,” Burch said. Kentucky 31 tall fescue has been quickly adopted by cattle producers since its release in 1943, and it now inhabits an estimated 40 million acres in the United States, he added.